I have a SVT pro-3 that I use for small venues and practices and I have a SVT pro-4 that I use for larger venues.
The pro-3 can be used with a 4 or 8 Ohm speaker load. I use it with a 4-10 and a 1-15 ampeg speaker cabinets at 4 ohms.
I use the pro-4 with an ampeg 4-10 HLF and a 1-18 for...